State reasons for the following :
(a) Tap water conducts electricity, distilled water does not.
(b) Dry hydrogen chloride does not turn blue litmus to red where as dilute hydrochloric acid does.
(c ) During summer season, a milk man usually adds a very small amount of baking soda to fresh milk
(d) For dilution of acid, acid is added into water and not water into acid.
(e) Ammonia is a base but does not contain hydroxyl group.

Explanation

(a) Tap water contains ions which conduct electricity whereas distilled water does not contain ions.
(b) Dry HCl does not form ion but Hydrochloric acid gives `H^(+)` and `Cl^(-)` ions, this turns blue litmus to red.
(c ) Baking soda does not allow milk to change to lactic acid which makes milk sour.
(d) Adding water to acid is highly exothermic due to which the glass container may break. Therefore acid is added to water very slowly with constant stirring to overcome heating.
(e) Ammonia dissolves in water and form `OH^(-)` ions, therefore it is basic.
`NH_(3) + H_(2)O rarr NH_(4)^(+) + OH^(-)`